Drawer ejector device

ABSTRACT

A device for moving drawers out of and into filing cabinets, particularly mechanized filing cabinets in which a number of drawers are transported by carriers translated via a continuous loop conveyor mechanism. A unique lever system is mounted adjacent a drawer access area in the vicinity of the loop of the conveying mechanism. Suitable connection means are provided to operatively couple the lever system to the rear portion of any drawer selectively positioned in the access area. The lever system is adapted to either eject a carried drawer through the opening or retract a previously ejected drawer onto its respective carrier.

United States Patent [1 1 Hock et a1.

[ Jan. 28, 1975 1 DRAWER EJECTOR DEVICE [73] Assignee: Sperry Rand Corporation, New

York, NY.

[22] Filed: Mar. 22, 1973 [2]] Appl. No.: 343,899

[30] Foreign Application Priority Data [58] Field of Search 312/21, 28, 223, 270-271, 312/294, 301, 330

[56] References Cited UNITED STATES PATENTS 1,953,024 3/1934 Rand 312/28 2,836,968 6/1958 Ferris... .1 312/223 UX 3,009,458 11/1967 Poarce 312/223 UX 3.011,850 12/1961 Davis 312/223 X 3,105,727 10/1963 Anders 312/223 3,224,825 12/1965 Sturgis ct a1. 312/223 3,306,691 2/1967 Graber et a1 312/223 3,532,405 10/1970 Anders 312/223 3,537,768 11/1970 Anders 312/223 Primary Examiner-Paul R. Gilliam Attorney, Agent, or Firm-Eugene T. Battjer [57] ABSTRACT A device for moving drawers out of and into filing cabinets, particularly mechanized filing cabinets in which a number of drawers are transported by carriers translated via a continuous loop conveyor mechanism. A unique lever system is mounted adjacent a drawer access area in the vicinity of the loop of the conveying mechanism. Suitable connection means are provided to operatively couple the lever system to the rear portion of any drawer selectively positioned in the access area. The lever system is adapted to either eject a carried drawer through the opening or retract a previously ejected drawer onto its respective carrier.

6 Claims, 7 Drawing Figures WWW SHEET 10F 3 DRAWER EJECTOR DEVICE BACKGROUND OF THE INVENTION Many prior devices in the mechanized filing cabinet art operate with very complicated mechanisms subject to malfunction. Some of these prior art devices do not provide parallel guidance of the drawers. However, in order to avoid jamming or locking of the drawers, the drawer guides must be correspondingly designed or additional means for parallel guidance of the drawers must be provided. v

Ejector devices acting on a drawerat only one power transfer point are disadvantageous, especially if the line of power action does not go through the center-of-mass of the drawer, or when the drawer is heavily or unequally loaded; a further problem in the design of drawer ejector devices is posed by the small space available for such devices in filing cabinets. In order to avoid an increase in the standard depth of the filing cabinet and to make as much use as possible of the volume of the filing cabinet for storing of files, cards or other goods, only a very small space behind the drawers should be used for the ejector device.

US. Pat. No. 3,298,766 issued Jan. 17, 1967 to C. D. Graber et al., is exemplary of prior art devices that operate with a flexible drive element. As the drive element is subjected to pressure at least when the drawer is ejected, there exists the danger that the flexible drive element will buckle out. In addition the relatively large friction forces present can easily cause malfunctions.

In US. Pat. No. 3,297,378 issued Jan. 10, 1967 to N. J. Krug et al., a drawer ejector device is described in which a flexible element is moved by means of a gear rack drive for ejecting and retracting drawers. In this type of prior art device it is possible to work only with small velocities, unless the disadvantage of jerky starting and stopping is tolerated.

To avoid the described difficulties of prior art de vices, drawer ejector devices have been proposed, which are not arranged behind the drawers, but in front of the drawers where the drawers are engaged by means of a locking device in the front thereof to pull them in direction to the operator. Such designs are not only ugly looking but are also impractical, because they occupy space in front of the work table and therefore hinder the operator.

In view of the above discussed state of the art it is an object of the present invention to provide a drawer ejector device which can easily be located in a small space behind a drawer, and which also provides a good parallel guidance of the drawer.

BRIEF SUMMARY OF THE INVENTION The present invention contemplates a drawer ejector device for moving drawers or the like out of and into a cabinet, particularily a mechanized filing cabinet, and is characterized in that behind the drawers a lever system is provided. The lever system comprises at least two levers connected pivotally together in the form of a cross and having four power action points provided by two pivotal bearings and two slide blocks. The latter blocks are movable in transverse guides transverse to the direction of motion of the drawer. A first transverse guide and a first pivotal bearing are associated with a support in the frame of the cabinet and a second transverse guide, and a second pivotal bearing are associated with a movable connection bar, so that on a movement of the drawer the connection bar is always kept at a right angle to the direction of the movement of the drawer.

In a principal embodiment of the invention the lever system is symmetrically arranged in that the levers are pivotally connected in the middle in an X-like manner. One of the levers is slidably coupled at one of its ends by means ofa slide block in a transverse guide toa support. Its other end is pivotally coupled with the connection bar. The other lever is pivotally coupled at one of its ends to the support and at its other end is slidably coupled by means of a slide block in a transverse guide to the connection bar. When using the ejecting device in a mechanized filing cabinet it is mounted with its support in horizontal position in the narrow space within the loop of the container conveying chain and is provided, depending on the space available, with a symmetrical or an asymmetrical lever system.

A further embodiment of the ejector device contemplates a drawer cabinet having drawers in a stationary frame and is characterized in that the ejector device with the drive unit is arranged vertically movable behind the drawers for selection of the desired drawer. Regardless of the application, by designing the lever system consisting of at least two crossed levers pivotally connected together, it is possible to obtain a very small depth of the drawer ejector device in the direction of operation. Accordingly, the device can be built into the very narrow space behind the drawers of any filing cabinet. Further, the lever system, permits a relatively simple drive mechanism which can operate without friction and provides a motion of the drawer ejector device optimally adapted to the drawer motion. The connection bar makes it possible to transfer power to the drawer at at least two points, so that also heavy and unequally loaded drawers can be moved without jamming. The lever system can be modified, so that different depths of drawers and ejecting paths can be realized for a given width of the drawer cabinet.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a plan view of the principal embodiment of the drawer ejector device in partly extended position.

FIG. 2 shows a plan view of the drawer ejector device in the retracted position.

FIG. 3 shows a part of the drive unit.

FIG. 4 is a partial side view showing the drawer ejector device associated with a drawer in the ejected position.

FIG. 5 is a perspective view of a drawer cabinet suitable for the invention and showing a row of ejected drawers.

FIG. 6 shows an asymmetrical lever system according to another embodiment of the drawer ejector device.

FIG. 7 is a graphic representation of the ejecting operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawer ejector device shown in FIG. 1 comprises a lever system with two levers A and B. Both levers A and B are preferably pivotally connected in the middle M. Two end-points l, 5 of the four end points 1, 3, S, 7 of the levers A, B are connected with the stationary support 9, and the other two end points 3, 7 are connected with the movable connection bar 11. The support 9 as well as the connection bar 11 have a transverse guide, for instance in the form of a slot 13, 15, and a pivotal bearing 17, and 19. The connection of the levers A, B with the support 9 and the connection bar 11 is made in such a way, that each end 3, Sis pivotally supported and that the opposite ends 1, 7 are supported for transverse movement in the transverse guides 13, 15 by means of the slide blocks 2, 8. Lever A is with its end 3 pivotally supported on the connection bar 11 and slidably supported with its other end 1 in the transverse guide 13 by means of the slide block 2. Lever B is with its end 5 pivotally supported on the support 9 and with its other end 7 slidably supported by means of the slide block 8 in the transverse guide of the connection bar 11. The pivotal support of the end points 5, 3 on the support 9 and the connection bar 11 respectively, is preferably made by means of the pivotal bearings 17 and 19, respectively. As the levers A, B are rigid, their end points 1, 3, 5, 7, on a transverse movement of the end points 1 and 7 in the transverse guides 13 and 15, lie always in the corners of an imaginary rectangle, one side of which is parallel to the support 9, and the opposite side parallel tothe connection bar 11. As the support 9 is connected with the frame of the drawer cabinet, it follows that on a drawer movement the end points 1,7 of the levers A,B are moved along the transverse guides 13,15 thereby holding the connection bar 11 parallel to the support. It can further be seen, that for obtaining the described movement by a forced movement of the end point 1 the lever system can be driven with the slide block2 gliding along the transverse guide 13. This drive is effected by the drive unit 21. In order to obtain the desired drawer movement, it is of advantage that the lever system transforms the motion of the drive unit into a translatory motion perpendicular to the drive motion. This permits good use to be made of the very narrow space behind the drawers as a location for the drive unit.

The drive unit 21 may consist of an electric motor 23,

a gear drive,.preferably an angular gear drive 25, a

crank lever 27 and a drive lever 29. As FIG. 3 shows, the crank lever 27 is used to transform the rotational motion (arrow 31) of the electric motor 23 or the gear drive into the required translatory motion (arrow 33) of the end point 1 of lever A in the transverse guide 13.

To set the end positions of the ejector device and to stop the ejector device in these end positions, switching means 35 may be provided, said switching means being actuated by the drive lever 29 in the extreme positions 37 and 39 of the crank lever 27. The switching means 35 interrupt the current supply to the electric motor 23 until a new ejecting or retracting command is given by control means. Microswitches 35 may be used as switching means. The drive unit 21 and the switching means 35 for switching off the end positions are mounted on the support 9, which also comprises the transverse guide 13 and the pivotal bearing 17.

As mentioned above, the ejecting or retracting motion of a drawer 41 corresponds to the motion of the connection bar 11. The push or pull motion is transmitted by coupling means 43 from the connection bar 11 to the back wall 45 of a drawer 41. These coupling means 43 consist preferably of electromagnets, which, as will be explained hereinbelow, will be magnetized or demagnetized depending on the position of the lever system and the connection bar 11.

As can be seen in FIG. 1 and 4, the drawers are laterally guided eg by means of telescopic drawer guides 47. These drawer guides 47 are connected with the side walls 49 of the drawers or containers 41 and with a car rier 51 (FIG. 4) inside the cabinet. In the retracted position the ejector device is in the position shown by FIG.'2.

In front of the access opening 61 of the drawer cabinet 63 is a work table 65 as shown in FIG. 5. Ifa drawer 41 has to be ejected, the connection bar 11, by means of the coupling means, pushes the drawer 41 away from its carrier 51 and through the access opening 61. The end positions of the drawer 41 are determined by the extreme positions 37 and 39 of the crank lever 27, and are sensed by corresponding actuation of the switch 35 in these extreme positions. In the retracted condition the crank lever 27 is in the position 37, and the end points 1 and 7 of the levers A, B are at the left end of the transverse guides 13 and 15 (FIG. 2). In the extended condition, the end points 1 and 7 of the lever system will be at the right ends of the transverse guides 13, 15, and the crank lever 27 will be in the position 39.

The required path of motion of a drawer depends on the depth T (see FIG. 4) of the drawer and can be adjusted to the space conditions by proper dimensioning of the crank lever and/or the lever ratio of the lever system. To avoid an unhandy size of the crank lever 27, it is possible to modify the described lever system. If two levers A, B (FIG. 6) are used, the transmission ratio of the system can be changed in that both levers A, B are not pivotally connected in the middle, but, as FIG. 6 shows, at a point 69, both at the same ratio of division. In this case, the points 1', 3', 5', 7' of the levers A, B do not fall into the corners of a rectangle, but they form a trapezoid.

As it is also a feature of a trapezoid that the base line and the top line are parallel to each other, a parallel guidance of the connection bar 11 is also assured on this embodiment of the invention.

Another solution in this sense is the replacement of the described lever system consisting of two levers A and B by a multiple system of X-formed levers. For instance at the end points 7 and 3 of the described lever system a further X-like lever could be connected such that the end point of the latter corresponding to end point 1 is pivotally connected with the end point 7 of the first lever cross, and that the end point of the latter corresponding to end point 5 is pivotally connected with the end point 3 of the first lever cross. The end points of the second lever cross corresponding to points 3 and 7 could then be connected to the connection bar 11. Such a lever system has an ejection path of double length as compared to the ejection path of a simple lever system. In similar way, other designs are possible. It is also possible to combine translating lever systems. All such combinations can be used to replace the described lever system. They should always be arranged between the four power action points 1, 3, 5, 7.

As explained, the coupling of the connection bar 11 to the drawers 41 is made by electromagnets 43. In the retracted position, the electromagnets 43 are located at a certain distance from the back wall 45 of the drawer 41. If the drive unit 21 of the ejector device is set into operation by a corresponding command, the connection bar 11 together with the electromagnets 43 is moved to the back wall 45 of the drawer 41 and begins to eject it from its rest position on the carrier 51.

shortly after they have contacted the drawer 41. The

electromagnets 43 remain energized as long as the drawer 41 is moved out. The electromagnets 41 must in particular be active on retracting the drawer 41 into the cabinets 63. When the drawer 41 is again approaching its end position of the retracting movement, the proximity switch 73 is actuated switching off the electromagnets 43, so that the drawer 41 is released. Then the ejector device moves still somewhat further inward until the end switch 35 is actuated.

The small spacing, approximately mm, thereby created, is in particular necessary for the case where the ejector device is used in a filing cabinet having orbiting carriers 51 carrying drawers 41, which can be moved out. The spacing guarantees a contact-free motion of the carriers 51 of the drawers 41 when the ejector device is in the retracted position.

When the ejector device is used on a filing cabinet with orbiting carriers, it is preferably located inside of the cabinet between the lengths of the chain. Naturally, the space between the front length and back length of the chain is relatively narrowly limited, so that only this small interior room is available for a drawer ejection device. The location of the ejector device is preferably so chosen, that the support is horizontally mounted between the mounting and descending chain lengths. Therefore, after proper selection of a carrier, the lever system can eject the drawers 41 located on the carrier to the work table 65. This is schematically indicated in H0. 4.

The invention, which has been represented and discussed in several embodiments can be used for all kinds of drawer cabinets, especially for drawer cabinets with orbiting carriers, where there is only little space for an ejector device. The ejector device is very simple and very reliable in operation. The drive unit permits a relationship between speed and travel path very well suited to the existing conditions. According to FIG. 7, when the electric motor 23 or the gear train 25 has a constant speed the ejecting motion is at first slow, then fast and towards the end of the movement of the drawer 41 again slow. Points 37 and 39 correspond to the two extreme positions of the crank lever 27, the intermediate positions of which are indicated on the Y-axis. The X axis represents the path of the ejecting motion, and the curve 75, a turned sine curve, shows the relationship. This favorable speed distribution is a result of the transformation of the rotary motion of the drive unit 25 into a linear motion of the slide block 2, and therefore of the end point 1 of the lever A, caused by the crank lever.

The mounting of the ejector device in a filing cabinet with orbiting storage containers has already been described. lf the drawer ejector device shown is used on a drawer cabinet with stationary rows of drawers, it is advisable to make the support 9 vertically movable inside the cabinet behind the drawers, so that by a corresponding upward or downward movement of the whole ejector device the row of drawers to be ejected can be selected and then ejected.

We claim:

1. In a mechanized storage cabinet of the type in which a plurality of drawers are transported on carriers selectively positionable at an opening in the cabinet by controlled motion of the carriers along an orbital path on a continuous loop conveyor mechanism, apparatus for ejecting and retracting through. the cabinet opening a selected drawer on a carrier positioned at the opening comprising:

support means mounted interiorly of the cabinet and extending lengthwise behind a drawer located at the cabinet opening, said support means including a guide extending partially along the length of the support means normal to the direction of drawer motion and a slide member mounted for motion along said guide,

connection means disposed between the support means and the rear of a drawer at the cabinet opening, so as normally to be spaced from the rear of a retracted drawer to permit unimpeded motion of the orbiting carriers formoving a selected carrier to the cabinet opening, and extending lengthwise of the drawer so as to contact the rear wall of the drawer on at least two points disposed about the drawer center upon being moved into engagement with the drawer, said'connection means including a guide extending partially along the length of the connection means normal to the direction of drawer motion and a slide member mounted for motion along said guide,

a lever system located substantially in a horizonital plane coupling the support means to the connection means, said lever system including first and second levers of equal length pivotally connected together at least at one point intermediate the ends of the levers, the first and, second levers being pivotally connected at one end at spaced positions along the support means and pivotally connected at the other end at spaced positions along the connection means such that one end of the first lever is connected to the slide member in the guide of the support means for translation therealong and an end of one of the first and second levers is connected to the slide member in the guide of the connection means, and

drive means fixedly secured relative to the support means interiorly of the cabinet and disposed laterally of the guide in the support means, said drive means including a motor and crank mechanism coupled to said first lever for converting the motor rotational motion to an oscillatory motion of the slide member along the guide of the support means whereby motion of the support means slide member toward the pivotal connection point of the second lever on the support means causes a scissor like action of the levers to move the connection means into contact with the drawer for ejection thereof through the cabinet opening while motion of the support means slide member away from the pivotal connection point of the second lever on the support means causes the connection means to withdraw back into the cabinet.

2. The apparatus of claim 1 wherein the first and second levers are straight members pivotally connected at only one point intermediate the ends, the first lever is connected to the connection means at the end opposite the end connected to the slide member of the support means, and the second lever is connected to the slide member of the connection means at the end opposite the end connected to the support means.

3. The apparatus of claim 2 wherein the drawer rear wall comprises magnetically susceptible material and further including electromagnetic coupling means and a proximity switch affixed to the movable connection means, the proximity switch being operative to sense proximity of the movable connection means to the drawer rear wall for activating the electromagnetic coupling means to assure affirmative contact thereof with the drawer rear wall during ejection and retraction of the drawer.

4. The apparatus of claim 3 including limit switch means operatively associated with the driving means for sensing the fully ejected and fully retracted positions of the drawer to remove electrical excitation from the motor of the driving means.

5. The apparatus of claim 1, wherein the drawer rear the motor of the driving means. 

1. In a mechanized storage cabinet of the type in which a plurality of drawers are transported on carriers selectively positionable at an opening in the cabinet by controlled motion of the carriers along an orbital path on a continuous loop conveyor mechanism, apparatus for ejecting and retracting through the cabinet opening a selected drawer on a carrier positioned at the opening comprising: support means mounted interiorly of the cabinet and extending lengthwise behind a drawer located at the cabinet opening, said support means including a guide extending partially along the length of the support means normal to the direction of drawer motion and a slide member mounted for motion along said guide, connection means disposed between the support means and the rear of a drawer at the cabinet opening, so as normally to be spaced from the rear of a retracted drawer to permit unimpeded motion of the orbiting carriers for moving a selected carrier to the cabinet opening, and extending lengthwise of the drawer so as to contact the rear wall of the drawer on at least two points disposed about the drawer center upon being moved into engagement with the drawer, said connection means including a guide extending partially along the length of the connection means normal to the direction of drawer motion and a slide member mounted for motion along said guide, a lever system located substantially in a horizonital plane coupling the support means to the Connection means, said lever system including first and second levers of equal length pivotally connected together at least at one point intermediate the ends of the levers, the first and second levers being pivotally connected at one end at spaced positions along the support means and pivotally connected at the other end at spaced positions along the connection means such that one end of the first lever is connected to the slide member in the guide of the support means for translation therealong and an end of one of the first and second levers is connected to the slide member in the guide of the connection means, and drive means fixedly secured relative to the support means interiorly of the cabinet and disposed laterally of the guide in the support means, said drive means including a motor and crank mechanism coupled to said first lever for converting the motor rotational motion to an oscillatory motion of the slide member along the guide of the support means whereby motion of the support means slide member toward the pivotal connection point of the second lever on the support means causes a scissor like action of the levers to move the connection means into contact with the drawer for ejection thereof through the cabinet opening while motion of the support means slide member away from the pivotal connection point of the second lever on the support means causes the connection means to withdraw back into the cabinet.
 2. The apparatus of claim 1 wherein the first and second levers are straight members pivotally connected at only one point intermediate the ends, the first lever is connected to the connection means at the end opposite the end connected to the slide member of the support means, and the second lever is connected to the slide member of the connection means at the end opposite the end connected to the support means.
 3. The apparatus of claim 2 wherein the drawer rear wall comprises magnetically susceptible material and further including electromagnetic coupling means and a proximity switch affixed to the movable connection means, the proximity switch being operative to sense proximity of the movable connection means to the drawer rear wall for activating the electromagnetic coupling means to assure affirmative contact thereof with the drawer rear wall during ejection and retraction of the drawer.
 4. The apparatus of claim 3 including limit switch means operatively associated with the driving means for sensing the fully ejected and fully retracted positions of the drawer to remove electrical excitation from the motor of the driving means.
 5. The apparatus of claim 1, wherein the drawer rear wall comprises magnetically susceptible material and further including electromagnetic coupling means and a proximity switch affixed to the movable connection means, the proximity switch being operative to sense proximity of the movable connection means to the drawer rear wall for activating the electromagnetic coupling means to assure affirmative contact thereof with the drawer rear wall during ejection and retraction of the drawer.
 6. The apparatus of claim 5 including limit switch means operatively associated with the driving means for sensing the fully ejected and fully retracted positions of the drawer to remove electrical excitation from the motor of the driving means. 